Pauline E. Leary

Advancements in technology enable deployment of field-friendly gas chromatography–mass spectrometry (GC–MS), so the value of the technique can be realized at the sample site. A primary benefit of deployment to the scene is the ability to analyze trace levels of threats, providing real-time information to support scene safety and other intelligence, so mission-critical decisions using confirmed information may be made. This capability is especially useful in situations where a sample degrades, changes, or is unstable during storage or transport, or when access to a laboratory is not an option. When explosives are encountered on the battlefield, GC–MS may be useful. In this research, a variety of commercial, military, and homemade explosives were analyzed using portable ion-trap GC–MS. Data from both ion-trap and quadrupole mass-spectral libraries were compared to establish whether portable ion-trap GC–MS is useful for the identification of explosives. Ion-trap mass spectral data can be different from quadrupole data due to ion chemistry and other ion interactions, including space charge that may occur during ion trapping.  These results show that, although mass spectral data are sometimes different from quadrupole mass spectral data, portable ion-trap GC–MS is useful for performing confirmatory identification of explosives in the field. The forensic value of this capability is also considered.

	
	Portable gas chromatography–mass spectrometry (GC–MS) instrumentation has enabled the confirmatory analysis of explosive residues in the field. For battlefield forensics, portable GC–MS instruments are used for the detection and confirmatory identification of pre- and post-detonation threats. In addition, these systems provide information regarding the source of explosives based on the detection and identification of trace-level chemicals in the sample. The use of portable GC–MS is valuable for supporting scene safety, gathering intelligence, and providing investigative and adjudicative information about explosives events.

	It is important to recognize that GC–MS in the laboratory has historically been used for some of these same purposes, but there are significant benefits to performing the analysis at the scene. First, on-scene analysis enables the development of render-safe procedures based upon real-time threat identification and assessment. Second, intelligence turnaround time to support offensive operations is significantly improved. Commanders are empowered to make actionable decisions using reliable, confirmed information. Third, GC–MS results in real time can help guide and optimize scene processing. Finally, analysis at the sample site enables the most accurate evaluation of the scene. Results are representative of the scene at the time of analysis, not at some later date when samples are received and analyzed at the laboratory. This timeliness is especially relevant for this type of physical evidence, because, aside from the danger associated with storage and transport of explosive evidence, some explosives have relatively high vapor pressures, and will evaporate or sublimate during transport to the laboratory.

	Portable GC–MS systems were initially introduced to the market almost 25 years ago. Since this time, the design and performance of these systems has evolved (1,2), and there are currently a number of portable GC–MS options available to both scientists and non-scientists performing field analysis. These systems include both quadrupole and ion-trap designs. Quadrupole systems offer the benefit of generating classical mass spectra that are more easily interpreted and directly comparable with spectra in the National Institute of Standards and Technology (NIST) MS database. Ion-trap systems are desirable for field use, because they can run at higher operating pressures. The pumps required to achieve and maintain these higher pressures are more field friendly than the chemical pumps that were historically needed to achieve and maintain the operating pressures required of portable quadrupole systems. However, spectra generated using ion-trap systems may exhibit ion-chemistry events such as dimer formations occurring in the trap (2), and, therefore, are not always directly comparable with mass spectra within the NIST MS database. In addition, space charge is sometimes observed. Space charge occurs when the force of ion-ion repulsions inside the trap become too great, and can result in incorrect 

 assignments. Space charge further complicates spectral library matching. Library search results are frequently critical to end users of portable GC–MS systems who rely on library matching to achieve successful results in the field.

	To evaluate the potential use of portable ion-trap GC–MS analysis for the on-scene evaluation of explosive evidence, explosive standards were analyzed and compared with the proprietary library of the system and with the NIST MS database spectra to establish effectiveness of search results for these explosive standards. In addition, explosives samples received from international law-enforcement organizations were analyzed using portable ion-trap GC–MS, and results generated were reviewed to evaluate capabilities of the technology for analyzing the explosive-related components in these recovered samples.

	The portable GC–MS system used in this research directly links a low thermal mass resistively heated capillary column with a miniaturized toroidal ion-trap mass spectrometer (3–5). The GC column enables fast separation and thermal recovery (3-min analysis time) resulting in high throughput (approximately 5 min between injections). High throughput is always a desirable feature of analysis, but especially for field applications where scene-processing time may be limited or the scene itself may be dangerous. The toroidal ion-trap design is intended to increase trapping volume and, therefore, to minimize ion-ion repulsions. Regardless, the impact of both space charge and ion chemistry on the mass spectra generated may still be observed when using this system.

	The following equipment was used in this research:

		Smiths Detection Guardion portable GC–MS system with a GC capillary column; 5 m-long, Restek Corporation MXT-5 resistively heated, crossbond diphenyl-dimethylpolysiloxane, inner diameter 0.1 mm, film thickness 0.4 μm

		Leland Limited Incorporated disposable helium cartridge, 95 cc x 5/8 in helium filled, 2.4 g at 2500 psi

		Torion Technologies Custodian solid-phase microextraction (SPME) holder

		Supelco 23-gauge, 65-μm polydimethylsiloxane/divinylbenzene (PDMS/DVB) SPME fiber assembly

		Smiths Detection Guardion performance validation mixture sample

	Explosive standards were purchased from AccuStandard, Inc., in New Haven, Connecticut, and include:

		2,3-dimethyl-2,3-dinitrobutane (DMNB), 100 µg/mL in acetonitrile, CAS#3964-18-9

		2,4-dinitrotoluene (2,4-DNT), 1000 µg/mL in methanol, CAS#121-14-2

		ethylene glycol, dinitrate (EGDN), 100 µg/mL in acetonitrile:methanol (95:5), CAS#628-96-6

		hexamethylene triperoxide diamine (HMTD), 100 µg/mL in acetonitrile, CAS#283-66-9

		pentaerythritol tetranitrate (PETN), 1000 µg/mL in methanol, CAS#78-11-5

		1,3,5-trinitro-1,3,5-triazinane (RDX), 1000 µg/mL in methanol:acetonitrile (50:50), CAS#121-82-4

		triacetone triperoxide (TATP), 0.1 mg/mL in acetonitrile, CAS#17088-37-8

		1,3,5-trinitrobenzene (TNB), 1000 µg/mL in methanol:acetonitrile (50:50), CAS# 99-35-4

		2,4,6-trinitrotoluene (TNT), 1000 µg/mL in methanol:acetonitrile (50:50), CAS#118-96-7.

	Law-enforcement explosive evidence samples were received from various international law-enforcement organizations. These samples are detailed in Table I. The 20 samples are each from a different origin. The explosive type, as well as the sample description for each, was provided by the contributing organization. Aside from the details shown in Table I, no further information about the history of these samples was provided to the authors.

	Prior to all sampling, the SPME fiber was verified to be clean by performing an analysis using the GC–MS method described below. If chemicals were detected, the SPME fiber was continually cleaned by heating, until no chemicals were detected on the fiber. Explosive standard solutions were sampled using the direct-deposition method. Law-enforcement explosive samples were analyzed using either SPME headspace sampling, direct deposition, or both methods.

	Between 100 and 500 mg of sample was transferred to a GC–MS headspace vial. The vial was closed and then stored at 22 °C for at least 2 h. The headspace was then sampled by piercing the vial cap with the needle end of the SPME holder containing the SPME fiber and exposing the fiber for a specified period of time. Sampling times were variable and ranged from 10 min to 40 min.

	For explosive standards, explosive amounts between 20 and 200 ng were directly deposited using a microsyringe onto the coated portion of the SPME fiber, and allowed to dry for up to 5 min to allow evaporation of the solvent. Although attempts were made to control the amount of sample deposited onto the fiber, no attempts to provide quantitative analysis of these data were made. For law-enforcement samples, between 100 and 500 mg of sample was dissolved in 10 mL of acetone and stored at 22 °C for at least 2 h. Then, 10 µL of the sample solution was directly deposited using a microsyringe onto the coated portion of the SPME fiber, and allowed to air dry for up to 5 min, to allow evaporation of the solvent.

	Performance of the system was tested at the start of every work day. Performance testing evaluates GC, MS, and library search performance. To perform this testing, a standard containing 13 chemicals is analyzed. These 13 chemicals have expected retention-time values between 0 and 90 s. GC performance acceptance criteria requires that the retention times for all 13 chemicals must be the stated value ±2 s. MS performance includes tests for spectral quality, mass calibration, mass resolution, ion statistics, space charge, signal-to-noise ratio, and sensitivity. Library- search testing verifies the system is matching substances as expected against the system’s proprietary library. The system always passed all performance-test criteria prior to use. The performance-test procedure used was the procedure recommended by the instrument manufacturer.

	The system used in this research is deployed with a single GC–MS method. This method is linked to a proprietary library, as well as a condensed version of the NIST MS database. It is required that, if the user wants to search these libraries at the time of analysis, the deployed GC–MS method must be used. Although there is some deviation from that method that is tolerated, the use of some GC settings, including ramp rate, begin temperature, and begin hold time are required. This is because library search criteria use retention times when searching the proprietary library, and retention index when searching the condensed NIST MS database. It is possible to change these settings, but this would require either library development (if automatic library searches were required), or manual interpretations of GC–MS results.

	The method’s standard GC settings (which were used for this research) areas follows:

	A manual review of all data from the explosive standard samples was performed, and chromatographic peaks and characteristic mass spectra for seven of the nine samples were reliably detected. For these seven samples, detections were possible at both low and high concentrations, and at all inlet temperatures. For two of the nine standards, no chromatographic peak for the explosive was detected. In addition, expected target ions were actively searched in the region of their expected retention and across the entire chromatogram in each data file to confirm the negative findings of the chromatographic data review. Table II summarizes the detection results from the manual review of the GC–MS data from the explosive standards.

	RDX was not detected in the standard sample. As is described later, it also was not detected in any law-enforcement samples expected to contain RDX. Although no RDX was detected, it is assumed that the system in its current configuration is capable of detecting RDX because this substance is programmed into the proprietary library for the system. This library is purported to contain library data generated using the system with its deployed method. The library entry describes GC retention values and MS fragments consistent with those reported in the NIST MS database for RDX, so it is assumed the system is capable of detecting RDX, not just its degradation products, impurities, or other contaminants. The failure to detect this compound using the portable GC–MS may be due the inlet temperature or transfer line temperatures being too high. As has been reported by other researchers, the thermally sensitive nature of some explosives can cause them to degrade when introduced to the high temperatures of the inlet (6). To address this potential expectation, the systems inlet temperature was lowered to 210 °C, but no RDX was detected. It is likely that a method for this substance at even lower temperature would be required for its detection.

	HMTD was also not detected in the standard sample under any analysis conditions. It was also not detected in any of the law-enforcement samples, although none of the law-enforcement samples were expected to contain this explosive. In accordance with the NIST MS database, HMTD has an estimated non-polar retention index value of 1619, and its three most intense mass fragments at 

 values in descending order of intensity of 208, 88, and 45. As such, this explosive would be expected to exhibit a retention time in this portable GC–MS under these analysis conditions of approximately 101.5 s. No chromatographic peaks were observed at or around this retention time. It is also important to note that the entry for this explosive in the proprietary library of the portable GC–MS system listed the anticipated retention time of 34.4 s for HMTD (RI value of approximately 770), with its most intense mass fragments in descending order of intensity of 73, 74, and 44. The significant discrepancy between the retention values reported in the NIST MS database and the proprietary library entry of the portable GC–MS system indicate the entry in the proprietary library is not representative of HMTD, and is potentially a degradation product, impurity, or other contaminant.

	In addition to performing a manual review of the data, all GC–MS data files for the seven detected explosives were searched against the library of the portable GC–MS system. This search uses its own proprietary search algorithm. Of the seven samples detected, only six were in the library. For the six explosives in the library, an automatic identification of the explosive sample was reliably made. The automatic identification occurred at both low and high concentrations, and at all inlet temperatures.

	A search of each GC–MS data file for the seven detected explosives was also performed by comparing the mass spectrum at the chromatographic peak maximum of the explosive against the NIST MS database using the NIST MS database search software. For six of the seven samples, the highest probability hit always correctly identified the explosive substance. However, TATP was only identified as the top hit about 50% of the time. The ability to correctly identify TATP as the top hit against the NIST MS database was not attributable to sample load. It is important to note that searches against the NIST MS database only consider mass spectral data when generating a hit list. A summary of library searching results is shown in Table III.

	Finally, the mass-spectral data from the ion-trap system were manually compared with NIST MS database quadrupole spectra. In most cases, as is evidenced in the automatic library search results, no significant differences were observed between the two types of spectra. Figure 1 shows the mass spectrum from the portable ion-trap system, along with the NIST MS database spectrum of TNT. Although small differences in peak intensities were observed across the spectrum, these spectra are generally consistent with each other. The most significant difference between the ion-trap and quadrupole spectra were observed in the spectra of DMNB. The ion-trap spectrum of DMNB had an additional ion fragment at 

 130 that was not observed in the NIST MS database spectrum. This fragment had an intensity of about 13% of the most intense fragment in the spectrum (

41 was not observed in the ion-trap data. However, the ion-trap system is only specified to detect fragments of 

43 to 500. Therefore, not too much should be interpreted from its absence in this data. The ion-trap spectrum of DMNB from the portable ion-trap system and the NIST MS database spectrum of DMNB are shown in Figure 2.

	The TATP data was also reviewed to investigate the cause of the missed identifications when searched against the NIST MS database. It is likely that the missed identifications are due to the simplicity of the mass spectrum of this explosive. The most intense fragment in the NIST MS database spectrum is 

43, followed by fragments at 58, 59, and 70, which have relative intensities to 43 of 13%, 11%, and 10%, respectively. There are spectra of many chemicals within the NIST MS database that have very similar spectra to TATP. The incorrect identifications of TATP when searched against the NIST MS database were all from chemicals that had very similar spectra to TATP. It was possible to sometimes, but not always, exclude the missed identifications due to inconsistencies between the retention time observed in the chromatogram from the ion-trap GC–MS system and the retention index reported in the NIST MS database.

Law-Enforcement Explosive Evidence Samples

	Table IV details the explosive-related compounds included in the proprietary library of the portable ion-trap GC–MS system; Table V details the automatic library search results for the explosives-related identifications from the 20 law-enforcement samples. A manual review of all data was also performed. As previously mentioned, the system did not detect RDX. This is important because a number of samples contain RDX, including Semtex and C4. In addition, the system failed to automatically identify tetryl, even though tetryl was in the library. This is because this sample was slightly overloaded, and does not chromatograph well on this column. The poor chromatography coupled with column overload caused a shift in the observed retention time. This observed retention time was outside of the retention-time window of the library entry. Therefore, the substance was not identified.

	Aside from missing RDX and tetryl, the system returned a few false automatic identifications including for EGDN in two of the three samples of C4 and one of the six samples of Semtex, PETN in one of the three dynamite samples, dinitroglycerin in four of the six samples of Semtex, and RDX in both TNT samples. Identifications were considered false if no chromatographic peak was present, but the software identified the substance. Such a result may occur when spectra are noisy and the chemical for identification has few or common mass fragments. For instance, the proprietary ion-trap library entry for dinitroglycerin contains only three fragments with 

 values of 46, 76, and 64, at 100%, 8%, and 1% intensities, respectively. It is reasonable to expect that these three fragments will be present in noisy data.

	A review of the results also shows that there is value to analyzing explosive samples using both headspace and direct-deposition sampling. For instance, dinitroglycerin in dynamite samples was always observed in the headspace samplings, but never in the direct-deposition sampling. For TNT, DNT degradation products were observed in the headspace sampling, but not in the direct-deposition sampling. The reverse was true for the TNT that was not observed in the headspace sampling, but was reliably observed in the direct-disposition samples. The different results that occur from using the two sampling methods are not contradictory to each other; they enable a more complete assessment of the sample. Headspace sampling prior to sample dilution is useful for identifying the components of the sample with higher vapor pressures. Vapor-pressure values of explosives reported in the literature, for a number of reasons, are variable and sometimes contradictory (7–9), but Figure 3 summarizes the ranking order of vapor-pressure values of many explosives at 25 ËC, calculated by Ewing and associates after an extensive review of values reported in the literature. (8)

Articles

When explosives are encountered on the battlefield, the use of portable GC–MS is valuable for the detection and confirmatory identification of pre- and post-detonation threats. In addition, this technique provides information about the source of explosives based on the detection and identification of trace-level chemicals in the sample. The data presented here confirm this capability.

Optimized Explosives Analysis Using Portable Gas Chromatography–Mass Spectrometry for Battlefield Forensics

The majority of inmates in the United States are incarcerated for drug-related offenses. It is important that the technology used to test for controlled substances be accurate and reliable. For on-scene presumptive testing, color-based field tests are commonly employed. Numerous cases have been discovered where positive color-based field tests were later proven to be false positives via confirmatory laboratory testing. Portable infrared (IR) and Raman spectroscopy are capable of providing accurate and reliable identifications at the scene, but are not generally utilized for this purpose. This research evaluated important performance characteristics of these methods to determine which is best for conducting on-scene testing of cocaine HCl. This research concluded that although portable spectrometers require a large initial financial investment, their high performance characteristics (such as ease of use, rapid analysis, non-destructive capability, acceptable limit of detection, and minimal false positives and negatives) make them a superior tool to the color-based field tests for the on-scene presumptive analysis of cocaine HCl. Portable IR spectroscopy was determined to be better than portable Raman because of the lower limit of detection, less severe adulterant interferences, and Raman fluorescence of common drugs (such as heroin or additives).

	A detailed online investigation into field-based presumptive tests for illicit drugs revealed many cases where false-positive color tests at the scene resulted in the incarceration of innocent people. The case of Amy Albritton was detailed in a 

 article, and demonstrates the problem and its significance (1). A white "crumb" found in her vehicle was tested using the cobalt thiocyanate color test, and yielded a positive result for cocaine, although Albritton claimed innocence. Albritton was arrested, and pressured into taking a plea deal by her court-appointed defense lawyer, as he insisted that the test proved she was in possession of controlled substances and, thus, she would be better off taking the plea deal. She eventually complied, served her time in county jail, and went back to her life. It was not until months later that any confirmatory testing was done on the suspect crumb, and when it was conducted, it was concluded that the crumb was not a controlled substance. This, among other cases including those of Janet Lee (2), Antonia Carranza (3), and Karlos Casche (4), brings into question the reliability of color tests and indicates a need for finding superior methods for on-scene testing of controlled substances.

	There is a significant need for field drug testing to be accurate and reliable. This is because, in drug possession cases, outcomes are often decided before they even reach a trial through the use of plea bargains to obtain a conviction. Many US Courts accept guilty pleas based solely on the results of field tests, such as those in nine of the ten jurisdictions of North Carolina, and the cities of Atlanta, Dallas, Jacksonville, Las Vegas, Los Angeles, Newark, Philadelphia, Phoenix, Salt Lake City, San Diego, Seattle, and Tampa. Research indicates that at least 90 % of drug convictions are obtained through plea deals, with some even higher (94 and 97% in Tennessee and Kansas, respectively) (1). Due to the significant errors (such as false positives and interferents) associated with color tests, portable vibrational spectroscopy, including IR and Raman methods, may provide a superior alternative for field testing of illicit substances, especially since these methods offer a higher level of confirmation of the illicit substance.

	Portable IR and Raman spectrometers are both capable of identifying controlled substances, but have not seen widespread deployment by law enforcement for field testing, primarily because of the cost of the instrumentation. Another concern of the forensic science community is that nonscientist investigators would be executing scientific analyses at crime scenes, and may incorrectly conduct the test or misinterpret the results, or both. For field portable instrumentation to become a viable presumptive test for illicit drugs by law enforcement officers, the instruments need to not only be rugged, but simple to use by nonscientist personnel.

	Recently, the National Institute of Justice (NIJ)'s Forensic Technology Center of Excellence (FTCoE) published a landscape study of portable and handheld instrumentation for presumptive drug testing in order to provide background information for law enforcement who are interested in these technologies (5). This study is an excellent resource for information, but the authors did not perform any specific laboratory or field research for comparisons of the various technologies, and instead relied on literature searches, manufacturer specifications, and interviews with current users. There was no ultimate conclusion of this landscape study, as it was determined that portable technologies provide general benefits (versatility, objectivity, specificity, safety, chain of custody collaboration, technical support, and ability to be used for multiple applications), and challenges (high up-front cost, complexity, maintenance, limited mixture interpretation, and library dependence), and each jurisdiction has its own needs and circumstances.

	Performance characteristics were assessed and compared for each technique: the Narcotics Identification Kit (NIK) Test G for cocaine produced by Safariland, a Smiths Detection HazMatID Elite portable IR spectrometer with a diamond attenuated total reflection (ATR) sampling element, and a Smiths Detection ACE-ID portable Raman spectrometer. These instruments were used due to their availability, but the research could be applied to any company's comparable portable instrumentation.

	The specific performance characteristics that were evaluated for all methods included a limit-of-detection study, an investigation into specificity (potential false positives, false negatives, and adulterant interactions), and evaluation of the ease of use, speed of analysis, skill required of the operator, and destructive nature of the method.

	Two-component mixtures were created by using pure cocaine HCl (Sigma-Aldrich) as well as the following five adulterants: lidocaine, mannitol, caffeine, Sweet 'N Low artificial sweetener, and Enfragrow powdered baby formula. Samples with concentrations of 0.1, 0.5, 1, 5, 10, 25, and 50% by mass of cocaine HCl were prepared for experimentation. When portable IR and Raman analyses were conducted, samples of 35% and 15% were subsequently made to obtain more precise limits of detection.

	A positive result for cocaine HCl with the NIK test, as shown in the left side of Figure 1, was indicated by "blue or pink with blue speckles after breaking the first ampoule, a pink result after breaking the second ampoule and a pink layer over a blue layer after breaking the third ampoule (6)." If the proper color change did not occur (right side of Figure 1), this was noted as a negative result. A positive result for cocaine HCl with the portable IR and Raman instruments was indicated by a "hit" for cocaine HCl using the library search function on the instrument (Figures 2 and 4, respectively). If a "hit" was not provided, this was noted as a negative result.

	Before experimentation, pure samples of cocaine HCl, as well as each adulterant, were analyzed to establish controls, as well as ensure the adulterants were not false positives for cocaine HCl. It was found that lidocaine was a false positive for cocaine HCl with the color-based field test. Therefore, only the sample sets containing the other four adulterants were used for color testing experimentation.

	The limit of detection determined for the color-based field test was at a 10% concentration of cocaine HCl with all four adulterants tested. Sources have conflicting reports on the average purity of cocaine HCl found in street samples. In 2016, it was reported by the Colombian National Police that the purity of cocaine leaving their country was approximately 85%, but by the time the cocaine reached the UK, the purity was approximately 60% and dropped to about 30% at the retail level (7). The US Department of Justice released an article in February 2010 indicating that from 2006 to 2009, cocaine purity had decreased from 68.1% to 46.2%. Even if the lowest reported concentration of 30% were used as a reference, this would make the limit of detection for the color-based field test acceptable.

	An extensive literature review revealed numerous known substances that would provide a positive result with the cobalt thiocyanate test other than cocaine HCl (Table I), which is the basis for the color-based field test for cocaine. One article from the 

 listed 73 different compounds, indicating a large quantity of potential false positive results with the test (8).

	The color-based field test is a destructive method that prevents any further experimentation from being conducted on the sample used. It is simple to use, with directions provided in each box. The color changes are very obvious at high concentrations of cocaine HCl; however, at lower concentrations it can be difficult to discern the color of the bottom layer. The subjectivity of determining a positive result is a problem when there is ambiguity at low concentrations. This method would also not be viable for operators with a color-determination deficiency. A single analysis is fast, taking only a few minutes, and there is little adulterant interaction that affects the limit of detection. However, one sample may require several different tests to identify the illicit drug, thus taking more time than just a single analysis. Additionally, this test requires sampling of the specimen for testing, thus potentially exposing the user to an unknown substance. There is also no reproducible record of the testing, and the color results may degrade over time, although detailed documentation with photography is a possibility.

	The cost for the color-based field test for cocaine, crack, and free base is $25.50 for a box of ten tests. Other commercially available color tests cost between $2 and 5 dollars per test (5). As these tests are one-use only, whomever is employing the tests must buy a large quantity each year. The NIJ's landscape study estimated that a large metropolitan area has approximately 500 drug-related arrests per year, with two color tests being used for each arrest, resulting in a total cost of $30,000 per year. However, this does not take into account the number of cases where no arrest was made, due to a negative results with the color test. Further, the tests are only specific to a particular drug "group," so law enforcement personnel require separate color-based field tests for cocaine HCl than for marijuana, PCP, or opiates. These tests do have expiration dates, and cannot be stored indefinitely. Consequently, the $30,000 per year calculation is likely an underestimate of the actual cost. The perceived low cost of these tests is considered by law enforcement to be a significant benefit over portable instrumentation.

	Another factor is the potential litigation fees that could arise from someone who has been falsely convicted of drug possession. A person could file a civil suit, and those litigation fees could far outweigh the cost of investing in a more reliable method of presumptive testing at crime scenes. This does not include the non-monetary costs that come along with being falsely charged with drug possession due to a faulty test result, causing considerable personal distress.

	The limit of detection for portable IR using the on-board library search algorithm for mannitol, caffeine, and baby formula were at 25%. Below 25%, the instrument did not provide positive "hits" for cocaine HCl. For artificial sweetener, the instrument was able to detect cocaine HCl at 15%, and, for lidocaine, it consistently had limits of detection at 5%. When manual spectral analysis was conducted by an educated chemist in spectral interpretation, cocaine HCl was identified in all of the spectra below the established limit of detection for the instrument's search algorithm (Figure 3). This instrument provides a Reachback feature, where the user can electronically send a spectrum to a trained spectral interpreter for technical support at any time and day. This indicates that, even if the instrument does not provide a positive "hit," the user can receive technical support to assist with interpretation and troubleshooting. The spectra could also be sent to a forensic laboratory for interpretation, depending on the agency's protocols. Additionally, as previously mentioned, the lowest concentration of street cocaine HCl was reported to be 30%, which is higher than the limit of detection for the portable IR with all adulterants tested.

	There were no false positives or negatives identified with the portable IR spectrometer; however, there were a number of misidentifications found with the portable IR spectrometer. A 

 is any substance identified by the instrument that was wrongly identified in place of an authentic mixture component. There were also false identifications made in which an extra component was identified in addition to the known components that were not actually present in the mixture (called a "false hit"). Mistaken identifications are potentially a large point of concern, but only if these incorrectly identify or prevent the identification of a controlled substance. In this research, the majority of these false hits were extra identifications that were determined to be of innocuous substances. Ultimately, as long as the cocaine HCl is still being identified, an extra hit for something because of the adulterant being used does not necessarily affect the test results.

	IR spectroscopy is a nondestructive method. Portable IR instruments are simple to operate. Step-by-step prompts with icons are shown throughout an analysis. Although these instrument are easy to use and can be operated with little training, scientific knowledge is required for sample selection, evaluating the spectral quality, and trouble shooting. A large benefit over the color tests is the chain of custody corroboration in that when a sample is tested, the results are automatically stored and time-stamped in the instrument to be exported or reviewed later. Similar to the color tests, portable IR with ATR sampling requires direct testing of the specimen, thus potentially exposing the user to an unknown substance.

	Formal training would be required for the operation of a portable IR spectrometer. However, it is simple to operate, so the training could easily be incorporated into that already provided for officers. The analysis overall does not take more than a few minutes for each sample being run, which is comparable to the speed of the color-based field test.

	Though prices on portable IR spectrometers vary by company, model, and add-ons (such as libraries, attachments, and service), the price can range from $25,000 to $65,000. There are no consumables required for portable IR spectrometers, so this is a one-time, up-front cost. Additionally, these instruments are built to be rugged and used in high stress situations; this means that, though repair on the instruments may be necessary, they will not break easily and could be used for several years. Also, portable spectrometers have the capability to identify a large number of controlled substances. Instead of buying ten different color-based field tests and making sure a police department is stocked for an entire year with all of these options, one portable spectrometer could conduct the same analysis. Finally, an increased demand for these instruments would encourage companies to increase production, which could lead to a cost reduction, thus making it a more affordable technology.

	The limit of detection for the portable Raman spectrometer using the on-board library search algorithm was consistently 25% cocaine HCl for all adulterants. In most trials, the instrument could not detect cocaine HCl at lower percentages; however, it was able to detect as low as 5% with the artificial sweetener, and 10% with the baby formula. The ability to electronically send spectra to Reachback or to a forensic laboratory for manual spectral interpretation is also available for portable Raman spectrometers. However, for these samples, manual Raman spectral analysis did not enable lower detection limits.

	One of the advantages of Raman spectroscopy is the ability to analyze samples without making contact, analyzing through some containers made of clear glass and plastic bags. The ability to analyze substances contained within clear plastic bags was tested, and the limit of detection was unaffected, remaining at 25%. This limit of detection would be acceptable to detect the lowest reported concentration of cocaine HCl in street samples. Consequently, unlike color tests and portable IR spectroscopy, portable Raman does not require direct testing, thus reducing exposure to unknown substances.

	There were no false positives or negatives identified with the portable Raman spectrometer. As with the portable IR spectrometer, there were a number of "false hits" and misidentifications that occurred during analysis. The portable Raman analysis had significantly fewer misidentifications and false hits than the portable IR, with a likely explanation being the smaller onboard Raman spectral library, which limits misidentifications and false hits. Although none of the adulterants tested suffered from Raman fluorescence, it is important to recognize that other illicit substances (such as heroin) or adulterants may fluoresce, which would interfere with the ability for chemical identification of any of the mixture components. Dark-colored samples prohibit Raman analysis because they absorb the incident radiation, thus potentially destructively burning the sample. In this situation, an orbital-raster-scanning (ORS) Raman was used to minimize the transfer of incident radiation, but not all portable Raman systems use ORS Raman. These issues may prohibit Raman analysis for the identification of cocaine or other illicit drugs in the field.

	Similar to IR spectroscopy, Raman spectroscopy is nondestructive, requires only a few minutes for analysis, and creates a reviewable record of the analysis that provides chain-of-custody corroboration. Much like the portable IR spectrometer, it is a push-button method, with step-by-step instructions on the screen. However, there is a small spot size for analysis, and focusing the LASER can be challenging at times. Sometimes, a few attempts are necessary to get a viable spectrum of the sample. As with the portable IR spectrometer, formal training would be required for the operation of the portable Raman, which could be simply incorporated into general training that officers are given. The same caveat applies for both portable spectrometers: Despite their ease of use, there is a need for educated users for proper sampling and analysis.

	Portable Raman spectrometers are generally less expensive than most portable IR spectrometers, although there are some exceptions; thus prices range from $12,500 to $60,000. Similarly to IR spectrometers, these instruments are built to be rugged and do not require consumables, so this is a one-time, up-front cost.

	Portable spectrometers have excellent potential to be employed for the on-scene analysis of cocaine HCl. Performance characteristics were compared (Table II), and the advantages of portable spectroscopy over traditional color testing were demonstrated. The limit of detection for all three methods would be acceptable at the lowest reported purity of street cocaine HCl. The speed of analysis is comparable for all three methods, taking less than 3 min for each analysis. Portable IR and Raman spectroscopy methods are nondestructive, objective, and create a reviewable record for use as evidence in adjudications, which are significant advantages over color tests. Color tests are also more prone to false positives and negatives than tests using portable spectroscopy, thus the latter are more reliable for the on-scene analysis of cocaine HCl. Portable Raman also has the ability to identify cocaine HCl through some plastic bags, reducing the potential for contamination and risk of exposure to unknown chemicals by analysts. Color tests require less knowledge or skill from the operator, however, inserting training on the different spectrometers during general training for officers would be simple and feasible because the instruments are created to be user-friendly. Although color tests are generally thought to be less expensive than portable spectrometers, the total cost over several years is comparable, if not greater than, an instrument with only a one-time up-front cost.

	Of the two portable spectroscopic methods, the authors concluded that, although both technologies have similar performance characteristics, there are some features of portable IR spectroscopy that make it the preferred technique for on-scene cocaine HCl identification. The long and reputable history of IR spectroscopy means that there are more spectral libraries and the technology has had more time to be evaluated and perfected. Additionally, fluorescence and the inability to analyze dark samples lessens the utility of the portable Raman spectrometers, whereas a portable IR spectrometer is able to produce interpretable spectra for all specimens. Although these limitations were not a problem in the specific analyses tested in this research, they could prove to be prohibitive for identification by portable Raman of cocaine mixed with other adulterants and for the analysis of other drugs, like heroin. Portable Raman spectrometers have the advantages of being generally less expensive than portable IR spectrometers, as well as being able to analyze samples through some clear glass and plastics, thus providing greater safety for the analyst. Ultimately, both portable IR and Raman spectroscopy are viable alternatives for crime scene identification of cocaine HCl.

	(1) R. Gabrielson and T. Sanders, "How a $2 Roadside Drug Test Sends Innocent People to Jail" (July 7, 2016). Retrieved April 28, 2018, from 

https://www.nytimes.com/2016/07/10/magazine/how-a-2-roadside-drug-test-sends-innocent-people-to-jail.html

	(2) J. Kelly, "False Positives Equal False Justice" (2008). Retrieved April 28, 2018, from 

https://www.mpp.org/issues/criminal-justice/false-positives/

	(3) E. Peralta, "Thinking It Was Cocaine, N.C. Police Jail Man For Cheese And Tortilla Dough" (May 16, 2011). Retrieved April 28, 2018, from 

https://www.npr.org/sections/thetwo-way/2011/05/16/136359770/thinking-it-was-cocaine-n-c-police-jail-man-for-cheese-and-tortilla-dough?ft=1&f=1001&sc=tw&utm_source=twitterfeed&utm_medium=twitter

	(4) S. Jeong, "Man Spends Three Months In Jail After False Positive On Police Drug Test" (June 28, 2017). Retrieved April 28, 2018, from 

https://www.cnn.com/2017/06/28/us/drug-test-drywall-positive-arrest-trnd/index.html

	(5) Forensic Technology Center of Excellence. Landscape Study of Field Portable Devices for Chemical and Presumptive Drug Testing. U.S. Department of Justice, National Institute of Justice, Office of Investigative and Forensic Sciences (2018).

	(6) Safariland Group. NIK Test G- Cocaine, Crack, & Free Base (2018). Retrieved August 29, 2018, from 

http://www.safariland.com/products/forensics/field-drug-tests/nik-test-g---cocaine-crack-and-free-base-1006155.html#sm0000624lqmakerfrm2cnczoduu2

	(7) United Nations Office on Drugs and Crime. World Drug Report 2012. United Nations Publication, New York (2018).

 are with the Henry C. Lee College of Criminal Justice and Forensic Sciences at the University of New Haven, in West Haven, Connecticut. 

 is with the Wisconsin State Crime Laboratory, in Milwaukee, Wisconsin. 

 is with Smiths Detection, in Edgewood, Maryland. Direct correspondence to: 

On-scene analysis of cocaine is an essential tool for law enforcement. This study defines how portable infrared and Raman spectrometers are capable of providing accurate and reliable identification of cocaine and other drugs when and where needed most.

A Comparison of Portable Infrared Spectrometers, Portable Raman Spectrometers, and Color-Based Field Tests for the On-Scene Analysis of Cocaine

With the increasing proliferation of counterfeit drug products, there is an incentive to screen drugs for legitimacy. One method is to examine the tablet itself, which is usually a destructive operation. Another method that has been explored is to characterize the packaging, which enables nondestructive screening of the product. Raman microscopy has been found to be a useful tool, and it is often the tool of choice for these measurements. Raman mapping of tablets enables not only the identification of components, but also the mapping pattern can enable matching manufacturing sites of different tablets. The study of packaging materials can provide an identification of coating and a depth-profile measurement of thickness. In addition, unlike Fourier transform infrared spectroscopy, which can only measure surface materials, Raman microscopy can provide spectra of dyes and pigments, even if they are printed below a surface film.

In this column installment, we present results of tablet matching measurements and characterization of packaging. The examples show how these measurements aid in the detection of counterfeit drugs.  

Two tablets of a well-known drug product were acquired, one from a pharmacy in the United States and one via the mail from an internet pharmacy. Initially, maps of the entire tablets were produced using a DuoScan Raman imaging system (Horiba Scientific) with a 10× objective and a 200-μm pixel. Although maps were acquired in reasonable amounts of time, there did not seem to be any variability in the data. That is, on the 200-μm scale, the tablets were homogeneous, at least for this product. So, smaller maps were collected to make chemical and textural comparisons. This work was performed on an Evolution Raman microscope (Horiba Scientific), an 800-mm focal length system, using a 600-grooves/mm grating, and a 532-nm laser. Maps were acquired in the fingerprint region (200–1800 cm

). LabSpec multivariate analysis software (Horiba Scientific) was used to create the Raman maps, using either the classical least squares (CLS) algorithm when identifiable species could be seen in the data set, or the multivariate curve resolution (MCR) algorithm when the chemical factors were not apparent. As the results will show, operating on the two data sets independently produced verification of the conclusions.   

In reality, it was Witkowski of the Food and Drug Administration (FDA) Forensic Chemistry Center in Cincinnati, Ohio, who originally proposed the use of Raman mapping for identifying chemical species and morphological distribution as a means of differentiating counterfeit from authentic tablets, and for differentiating counterfeits from various manufacturing sites (1). Since that work was done, developments in mapping hardware have improved data collection times and multivariate software provides better quality images resulting from the use of scores mapping rather than intensity between cursors, which is subject to much more noise.  

Figure 1: Left: Raman maps of tablet purchased from a pharmacy in the United States produced with fingerprint spectra (top) and CHâOH spectra (bottom). Right: Spectral loadings used to create the maps on the left. The red species is presumably the active drug, having bands near 1600 cm-1 and above 3000 cm-1 that indicate unsaturation. The reference spectrum shown in dark green is that of a cellulose paper filter.			

Before data collection, the tablets need to have the coating (usually opaque and pigmented) removed and the surface flattened. The maps shown in Figures 1 and 2 were acquired with step sizes between 5- and 15-μm, using the DuoScan Raman imaging system to distribute the laser intensity over each pixel in the map. The SWIFT imaging option (Horiba Scientific) was used to further reduce the acquisition times by eliminating stop and start operations at each data point. After the acquisition of a map, the entire hyperspectral cube was baseline-flattened to improve the quality of the multivariate results. Then we either surfed the file to identify regions of homogeneous spectra that could be used with the CLS algorithm or the MCR algorithm was invoked to "find" the spectral components in the file. Figures 1 and 2 show maps for each of the two tablets based on the fingerprint spectra and then the CH–OH spectra. The loadings ("spectra") used to produce the maps are also shown with reference spectra of the excipient presented for comparison. Because the identity of the active pharmaceutical ingredient (API) was not known, its spectrum could not be shown for comparison. However, APIs tend to be aromatic with large intensities above 1500 cm

; the loadings shown in red in Figures 1 and 2 are presumed to be API and one can see that the red factors show the same spectra from the two tablets. That is, the counterfeit tablet did contain the active ingredient.  

Figure 2: Left: Raman maps of tablet purchased over the internet produced with fingerprint spectra (top) and CHâOH spectra (bottom). Right: Spectral loadings used to create the maps on the left. The red species is presumably the active drug, having bands near 1600 cm-1 and above 3000 cm-1 that indicate unsaturation. The reference spectrum shown in green is that of lactose. Note that use of the MCR algorithm in the CH region identified the presence of a third species (shown in grey) whose spectrum is similar to that of Mg stearate.			

Note that for the internet sample, whose results are shown in Figure 2, the CH–OH map has more morphological detail than the fingerprint map. Also, the use of the MCR algorithm revealed the presence of a hydrocarbon like magnesium (Mg) stearate. If we go back to the fingerprint map and examine the spectrum in the region where Mg stearate appeared in the CH region, then that component can be added to the factors, producing the map shown in Figure 3. Surprisingly, in this case the CH–OH region provided more information than the fingerprint region, as originally examined. We believe that this is because the fingerprint region will be dominated by the unsaturated API, whereas in the CH region, all species have similar intensities.  

Figure 3: Left: Raman maps of tablet purchased over the internet produced with fingerprint spectra. Right: Spectral loadings used to create the maps on the left. The red species is presumably the active drug, having bands near 1600 cm-1 and above 3000 cm-1 that indicate unsaturation. Both excipient spectra (grey = hydrocarbon and blue = lactose) are heavily contaminated with the API probably because the materials do not segregate on this length scale. The reference spectra shown represent lactose in green, and Mg stearate in black.			

Examining the exterior packaging of drug products could provide a more rapid and nondestructive means of screening products for authenticity. The packaging of four samples was examined. To measure the inks and papers, it was necessary to use Raman spectroscopy instead of FT-IR because in FT-IR the radiation will not penetrate any coating present on the paper. Figure 4 shows the spectra of the blue and blue-green pigments on each package, after baseline subtraction. Band frequencies in the bottom spectrum are labeled to assign these spectra as resonance-enhanced. Under such circumstances, overtone and combination bands are strong, and CH stretches are usually nonexistent. For example, 2 × 1343 ≈ 2677 cm

. (Note that the matches are usually not exact because of anharmonicity of the vibrations.)  

Figure 4: Raman spectra of green or blue inks from pharmaceutical packaging of a drug product and three possible counterfeits of that product. Spectra were excited with the 633-nm laser line and detected on an Evolution Raman microscope (Horiba) equipped with a 600-grooves/mm grating. All spectra exhibited a fluorescence background, presumably from the pigment itself; spectra were baseline-corrected for the display.  			

The three bottom spectra in Figure 4 appear to be quite similar. Although the bands in the top spectrum do coincide with bands in the other samples, some of the spectral bands in the bottom three samples are absent; in particular, small bands at 1269 and 1487 cm

  are missing. In the absence of information on the pigments, one can presume that the unsaturated cores of the molecule that provide the color are quite similar, with some small (unsaturated) modifications which would account for small spectral differences.  

Figure 5: Raman spectra of white regions from pharmaceutical packaging of a drug product and three possible counterfeits of that product. Spectra were excited with the 633-nm laser line and detected on an Evolution Raman microscope (Horiba) equipped with a 600-grooves/mm grating. Spectra were baseline-corrected for the display. 			

Figure 5 shows spectra acquired from the noncolored regions of the same packages. There is a one-to-one correspondence between Figures 3 and 4; that is, the top spectra on each figure come from the same sample, and likewise for the other spectra. Again, one can see that the top spectrum is an outlier.  

Figure 6: Raman spectrum of white region of one of the packaging samples (top, red) superimposed on a reference spectrum of polypropylene (middle), and calcite (bottom). 			

The goal of these measurements was to determine if the packaging materials could be differentiated, and obviously that is documented. But since we have been looking at spectra for so long, we always like to challenge ourselves and see if we can guess what is present. Clearly, that is a frightening idea for the novice who is looking for quick answers to a problem. So, at this point we want to show how current commercial products can alleviate the need for highly experienced spectroscopists. We looked at the spectra of the white packaging and recognized the presence of calcite and polypropylene. Figure 6 shows the bottom spectrum of Figure 5 superimposed on our reference spectra of calcite and polypropylene. It is easy to see that most of the spectral features and intensity can be accounted for by these two species. However, the interesting thing was to determine what the BioRad KnowItAll software (2) (BioRad Laboratories) and database could do with this spectrum. Figure 7 shows the results of a mixture analysis performed in that software. The top part of the figure shows the components that were used to fit the spectrum; note that although we were aware of the calcite and polypropylene we were not aware of the polystyrene until the mixture analysis pointed out its presence. Each of these spectra are shown, as well as the measured spectrum and the residual from the fit. Note that because of the tendency of polymers to orient, the relative intensities of the various bands will vary from measurement to measurement, so most of the features in the residual spectrum are not of concern. In addition, the weighting column at the top of the figure shows the relative contributions that were used to fit the measured spectrum. The bottom part of Figure 7 shows, in more detail, the measured spectrum superimposed on the composite spectrum.  

Figure 7: Results of the mixture analysis in the KnowItAll software. The bottom of the figure shows the measured spectrum (in black) superimposed on the composite spectrum (in red) which is constructed using the pure spectra shown in the top of the figure			

In the first part of this column installment, we showed that Raman images constructed from 

 maps of tablet surfaces can provide information both on the composition of the tablets and the components' distribution pattern, both of which can help determine if a sample is authentic or not. In addition, differences can aid in determining if counterfeit samples have a common origin. In the second part of this column, we showed that spectra of the packaging material, which can be recorded without any sample destruction, can also aid in the identification of counterfeits. In addition, for those who want to be able to identify material from the spectra, we showed how the use of commercially available software can provide identification, even for a mixture sample. 

(1) F. Adar, E. Lee, and M. Witkowski, "Single Point Analysis and Raman Mapping of Dosage Formulation as a Means for Detecting and Sourcing Counterfeit Pharmaceuticals," presentation at Pittcon 2007. 

(2) Bio-Rad Laboratories, Inc., Philadelphia, Pennsylvania, 2014. 

 is the Principal Raman Applications Scientist for Horiba Scientific (Edison, New Jersey). She can be reached by e-mail at 

 is the applications manager for the Americas for the chemical and biological product line at Smiths Detection. Prior to holding her current position at Smiths, Pauline worked as a pharmaceutical R&D scientist at Purdue Pharma in Ardsley, New York. Pauline holds a B.A. degree from Marist College, an M.S. degree from John Jay College of Criminal Justice, and a PhD from the Graduate Center of the City University of New York. 

 is an Associate Professor of Forensic Science and Chemistry at John Jay College and the Graduate Center, CUNY. He has been in the academic world for more than 15 years after completing 23 years in a municipal crime laboratory. His research interests are in the applications of light and electron microscopy along with UV–vis and vibration spectrometry to the analysis of micro and ultramicro samples. 

Results of tablet matching measurements and characterization of packaging are presented.

Raman Microscopy for Detecting Counterfeit Drugs — A Study of the Tablets Versus the Packaging

The authors discuss the use of vibrational spectroscopy to differentiate an authentic article from a counterfeit one throughout a product's lifecycle, from component receipt at the site of manufacture, to product receipt by the end user.

While the challenge of facing this type of illicit activity might seem overwhelming for a variety of reasons, the need to do so has never been more critical. Aside from the loss of revenue, there are other considerations that are just as significant. Many of these counterfeit products pose a significant threat to health and safety due to substandard quality control, and some have even been shown to be harmful to the user (2). Counterfeiting and piracy also have a long-term negative impact on innovation and brand recognition, and channel a considerable portion of revenue to criminal networks, organized crime, and other groups that disrupt and corrupt society (3). In addition, intellectual property in the form of copyrights, patents, and trademarks promotes cultural development, fosters innovation and growth, and protects public health and safety (4). Theft of these goods affects all industry sectors and results in substantial economic, social, and developmental costs that have increased exponentially in recent years. Piracy and counterfeiting have been shown to decrease employment opportunities, diminish tax revenues for governments, and reduce incentives to invest (5). 

Product Authentication Using Analytical Chemistry

Defense of intellectual property assumes that it is possible to differentiate an authentic article from a counterfeit one. Frequently this is a relatively simple task. As counterfeiters become more experienced in their trade, though, differentiation becomes more and more challenging. In many instances, it is necessary to perform chemical analysis before a conclusion about authenticity can be made. In addition, due to the complex nature of the lifecycle of a counterfeit article, it has become necessary for brand owners across many different industries to employ methods for detection and authentication at various levels within their legitimate supply chains. For instance, in the pharmaceutical industry, many companies employ in-house forensic scientists to address product authentication concerns. Within the textile industry, safeguarding the integrity of natural organic fibers is an absolute requirement, as contamination with pesticide-tainted counterfeits undermines quality and, ultimately, revenue. In the electronics industry, counterfeiting has been a problem for a long time, but the current economic challenges appear to be making things even worse. The industry has even begun to adopt practices like qualifying reliable vendors to help prevent counterfeits from entering their supply chain and marketplace. Although this is a common practice in the pharmaceutical industry, it has been adopted only recently within the electronics arena. 

The level of testing performed to determine authenticity is variable, but there are analytical methods known to be effective at providing proven results that enable effective chemical differentiation. For instance, vibrational spectroscopy in the form of both infrared (IR) and Raman spectroscopy has been used with success to perform chemical identifications on both the counterfeit article itself and on the packaging used for transport of the article (6). Figure 1 shows the IR spectra collected from packaging from genuine and replicate medications. These spectra show that the chemical information contained within an IR spectrum frequently can be quickly and easily (within seconds) used to differentiate the coating layer of packaging used. Differences between these two samples are evident across the range of the mid-IR spectrum. Analysis was performed using the IdentifyIR portable Fourier-transform infrared (FT-IR) spectrometer (Smiths Detection, Alcoa, Tennessee).  

Figure 1: Infrared spectra collected from the outside packaging of genuine and replicate samples. 

Vibrational microspectroscopy also can be used to differentiate components of the counterfeit product itself. Figure 2 shows the IR spectrum and photomicrograph collected from a cross-section of a genuine tablet, as well as the IR spectrum of a known reference standard of pseudoephedrine hydrochloride. These data show that the active pharmaceutical ingredient can be selected for microspectroscopic analysis using polarized light microscopy or other contrast-enhancement techniques. The coupling of the microscope with microspectroscopy makes it possible to collect spectra from discrete locations within a relatively complex matrix. In this instance, IR microspectroscopy was used to perform the chemical identification using an IlluminatIR IR microprobe (Smiths Detection). This IR microprobe allows the user to employ contrast-enhancement methods such as polarized light or fluorescence microscopy to visualize the sample and selectively isolate particles for microspectroscopic identification. It is also possible to use Raman microspectroscopy to perform a similar type of chemical analysis. Frequently, although not always, the chemical composition of counterfeit samples will not only have different excipients (nonactive components) from the replicate sample, but it might not even contain the active pharmaceutical ingredient at all (7). 

Figure 2: Infrared spectrum showing the active pharmaceutical ingredient contained within tablet cross-section. 

Product Authentication and Brand-Management Protection

Advances in technology make it possible to perform these and other types of chemical analysis, but protection of brand owner rights is not simply based upon detection of a counterfeit article when one presents itself. It relies upon maintaining control throughout a product's lifecycle. This can be a very difficult challenge, especially considering the global economy within which many commercial products are manufactured. Products frequently contain components from around the world, regardless of where final assembly or manufacture of the product might occur. The ability to establish control can be challenging in the best of circumstances and is almost always difficult to manage. The IntelliMark Solution product identification system (Smiths Detection in partnership with ARmark Authentication Technologies, LLC, Glen Rock, Pennsylvania) enables control and authentication of both the components used during manufacture or assembly and of the finished product. Product authentication can be verified anywhere along its lifecycle. 

The product identification system is a complex, customized product authentication solution that makes it possible for the brand owner to establish and maintain control by building it in at the beginning of the product's lifecycle. Information-laden, custom-designed covert markers are either incorporated into the raw materials and components, or they can be placed within the final product or its packaging and shipping containers. Product authentication can occur in transit or when the product is delivered to its final destination. The industries within which this technology can be applied effectively are virtually unlimited, ranging from the food industry, where the covert markers are manufactured using ingredients that are generally recognized as safe (GRAS) (8) for human consumption, to the electronics industry, where even fluorescent or other types of chemically elegant markers can be designed and used. 

Figure 3: Photomicrograph of covert marker (approximately 75 Î¼m) in the finished product for detection in transit or at final destination. 

Regardless of the industry served, the markers are detected easily using instruments designed to be used in the environments encountered along the supply chain. Figure 3 shows a covert marker (ARmark Authentication Technologies, LLC) detected using the IdentifyIR (Smiths Detection) spectrometer. This instrument is used in the laboratory or on the loading dock and is capable of both creating a visual image of the covert marker and collecting an IR spectrum for chemical identification of either the marker, the product, or its packaging or shipping container. Both the image and the IR spectrum can be used to set pass–fail criteria for authentication, which can be established as part of an interactive service between the brand owner and Smiths Detection. This interactive service is a critical component of the product identification system. The spectrum of the covert marker shown in Figure 3 as well as of the matrix within which the marker is incorporated is shown in Figure 4. 

Figure 4: Infrared spectrum of covert marker (red) and of the matrix (blue). 

Alternate wavelength light-source accessories can be used to help locate the covert markers when the markers are fluorescent, and also can serve as an additional level of security for authentication of the covert marker. Figure 5 shows the polymer matrix of an electronics board impregnated with covert markers. A handheld ultraviolet light source was used to induce fluorescence at the time this photomicrograph was collected. The type of covert marker offered is customized to meet the needs of the customer and can be simple or complex, depending upon the user's needs. 

Figure 5: Covert markers dispersed within polymer matrix visualized using an ultraviolet light source accessory with a digital microscope. 

In recent years, counterfeiting, piracy, and other intellectual property rights violations have grown in magnitude and complexity, costing businesses billions of dollars in lost revenue and often posing health and safety risks to consumers. This growth was fueled in part by the spread of enabling technology, allowing for simple and low-cost duplication of copyrighted products, as well as by the rise in organized crime groups that smuggle and distribute counterfeit merchandise for profit (9). Global access to the Internet also plays a critical role, especially with regard to accessibility to counterfeit pharmaceuticals. The Internet has become the primary tool for criminal organizations to advertise, communicate, and conduct sales of counterfeit pharmaceuticals, as well as being the primary mechanism for consumers to find, order, and make payments for counterfeit pharmaceuticals (10). Considering these and other facts, brand owners need to be vigilant about how they protect their intellectual property. Building control into a product's lifecycle provides the greatest level of security. These combined capabilities enable detection and authentication throughout a product's lifecycle from component receipt at the site of manufacture, to product receipt by the end user. 

is with John Jay College of Criminal Justice, CUNY, New York, New York. 

is with ARmark Authentication Technologies, LLC, Glen Rock, Pennsylvania. 

is with Smiths Detection, Alcoa, Tennessee. 

(1) The Economic Impact of Counterfeiting and Piracy, Executive Summary, 2008, 

http://www.ul.com/newsroom/anticounterfeiting/risk.html

(3) The Economic Impact of Counterfeiting and Piracy, Executive Summary, 2007, 

http://usinfo.state.gov/products/pubs/intelprp/protecting.htm

http://www.iccwbo.org/policy/ip/id2948/index.html

(6) Smiths Detection Application Brief AB-83, Trace Evidence Analysis Using the IdentifyIR Diamond ATR Spectrometer. 

http://www.usdoj.gov/dea/programs/forensicsci/microgram/mg0106/mg0106.html

http://www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/GuidanceDocuments/FoodIngredientsandPackaging/ucm061846.htm

http://www.ice.gov/pi/cornerstone/ipr/index.htm

(10) ICE Efforts to Combat Counterfeit Pharmaceuticals, Fact Sheet, July 11, 2006. 

Pauline E. Leary

Articles

Optimized Explosives Analysis Using Portable Gas Chromatography–Mass Spectrometry for Battlefield Forensics

A Comparison of Portable Infrared Spectrometers, Portable Raman Spectrometers, and Color-Based Field Tests for the On-Scene Analysis of Cocaine

Raman Microscopy for Detecting Counterfeit Drugs — A Study of the Tablets Versus the Packaging

Detection and Sourcing of Counterfeit Pharmaceutical Products and Consumer Goods